The successful treatment of schizophrenic behavior using antipsychotic tranquilizers such as chlorpromazine has stimulated research to find other neuroleptic agents having improved biological profiles. One such class of compounds is the hexahydropyrido[4,3-b]indoles. The basic ring structure is ##STR1## and the stereochemistry at positions 4a and 9b may be cis or trans. Examples of hexahydropyridoindoles that are useful as tranquilizers, neuroleptic agents, analgesics, sedatives, muscle relaxants and hypotensive agents are given in the following U.S. patents: U.S. Pat. No. 3,687,961; U.S. Pat. No. 3,983,239; U.S. Pat. No. 3,991,199; U.S. Pat. No. 4,001,263 and U.S. Pat. No. 4,141,980.
It has now been discovered that novel hexahydro-trans-4a,9b-pyrido[4,3-b]indoles substituted at the 5 position with an aryl group and the 2 position with an aminoalkyl group or an amidoalkyl group exhibit potent neuroleptic activity.